Tufted carpet and process for producing the same

ABSTRACT

A tufted carpet is described in which the tufting yarns (2) are tufted into a tufting backing (1) and firmly joined to it. The back side (1a) of the tufted carpet (1) has a layer (5) comprising pieces of thermoplastic plastic sheet material joined together under the influence of pressure and temperature. Back ends (2a) of the tufting yarns (2) are firmly bound into the layer (5).

This application is a §371 of international patent application Ser. No.PCT/EP93/00383, filed Dec. 2, 1993.

This application is a §371 of international patent application No.PCT/EP93/00383, filed Dec. 2, 1993.

The invention relates to a tufted carpet or carpeting having tuftedyarns tufted into a tufting backing and joined to it, and to a methodfor producing it.

Tufted carpets have a tufting backing and tufting yarns, tufted into it,which form loops on the back of the tufting backing. In a finishedcarpet, the loops are either left in that form or cut, then forming thecarpet pile. The tufting yarns are tufted relatively loosely into thetufting backing and extend intermittently parallel to the plane of thetufting backing. To assure that the tufting yarns will be retained inthe backing and will not pull out of it, such a carpet must be treatedwith latex. Latex coating systems are expensive, and in particular theactual latex coating process is followed by a complicating dryingprocess. They require rooms of a size on the order of 8 m×40 m. A dryingprocess presents problems of ventilation. In some cases, the operationof tuft insertion and coating with latex are even made separate from oneanother; that is, the tufted intermediate products are taken to aspecial coating system at a different place. This is disadvantageous andmakes the production process of such carpets more expensive.

U.S. Pat. No. 4,705,706 discloses a tufted carpet in which the tuftingbacking comprises three backing layers, for the sake of firmly anchoringthe tufting yarns. The solid connection of the tufted yarns to thebacking is achieved by heating during the production process. Theaforementioned tufting backing layers are needed to prevent thevulnerable carpet material from being destroyed by the effect of heat.

The object of the present invention is to embody a tufted carpet of thisgeneric type such that no latex is needed in its manufacture. The methodfor producing such a carpet should be economical and simple, whileavoiding the aforementioned disadvantages.

This object is attained by the invention as defined by the main claim.The process for producing such a carpet characterized in that pieces ofplastic sheet material are applied uniformly to make a layer on the backside of a tufting backing tufted with tufting yarns and are joined tothe tufting yarns and to one another under heat and pressure, causingfirm binding in the back ends of the tufted yarns.

The heat and temperature may be applied by a warm rolling or pressingoperation. The tufting backing may be needle-punched with bindingfibers, in particular polyethylene binding fibers, prior to the tuftingoperation. The tufting backing may be provided with an adhesive layerprior to the tufting process.

Furthermore, a secondary backing may be applied to the layer of piecesof thermoplastic material and may be joined to the plastic sheet layerby means of a simultaneous or subsequent warm rolling or pressingoperation, causing firm bonding of the back ends of the tufting yarnsinto the plastic sheet layer. That is, the object is attained by thetufted carpet or carpeting of the present invention which comprises atufted primary backing having pile tufts extending from one side thereofwith back ends of tufts on the opposite surface and thermally bonded tosaid opposite surface a layer composed of pieces of thermoplastic sheetmaterial wherein the pieces of thermoplastic sheet material have beenfused to the tufted backing under heat and pressure sufficient to embedsaid back ends in the layer and to the primary backing.

The tufted carpet according to the invention comprises a tuftingbacking, in which the tufting yarns, initially inserted loosely, arefirmly anchored by the provision that their back ends are bound into alayer, disposed on the back of the tufting backing, of sheet-likeplastic material in the form of piece goods, which has been made stickyby pressure and the effects of temperature. The tufting yarns are sofirmly joined to the tufting backing that the addition of latex is nolonger necessary, and the yarns do not pull out of the finished carpet.The back ends of the tufting yarns, as a result of the densificationand/or at least partial melting of the pieces of sheet material by theinfluence of pressure and heat, are firmly enclosed by the sheetmaterial; they are firmly bonded to the sheet material, which is in amolten state or sticky from the effect of heat.

If a still firmer bond of the tufting yarns in the tufting backing is tobe attained, then a binder layer, such as a needle-punched fiber bindinglayer, especially with binding fibers of polyethylene, is needle-punchedfrom the tuft side. The binding fiber layer forms an increased bindingvolume toward the tufting yarns from the underside of the carpet.

On the back side of the tufting backing, a second back can be applied ina simple way by means of the plastic sheet layer. It is placed over theplastic sheet layer and bonded to the tufting backing under theinfluence of temperature and pressure by the melting of the plasticmaterial. The second back thus applied not only contributes to bettersecuring and anchoring of the back ends of the tufting yarns, but alsoincreases both the elasticity in response to traffic, and the heatinsulation and noise abatement properties of the carpet.

It is advantageous if the pieces of sheet material is nonflat and is ofpolyethylene. As a result, the unbonded tufted tufting backing can bedensified by the effect of temperature and pressure, preferably byheating above the melting temperature of the plastic, such that thetufting yarns are "co-melted" in with the plastic material. Theapplication of a nonflat sheet material that has a high bulk volume issimpler than applying a layer of flat pieces of sheet. The sheetmaterial used can be increased in volume such that it is present inthree-dimensionally deformed form. In intrinsically flat sheets, anumber of places distributed over the surface can be stretched ordeformed in such a way as to produce protuberances and bumps. It is alsoadvantageous, however, that strips or pieces of sheetlike plasticmaterial that are already in nonflat form can be worked in jointly aswell. In particular, plastic sheet trimmings can be processed. Sincesuch sheets are processed with one another and with the tufting yarns byrolling or pressing, usually at elevated temperature, their differingproperties arising for instance from different materials, or theirthickness or color do not play any substantial role. What is essentialis the softening point, that is, the temperature at which the materialbecomes sticky and thus capable of bonding. At a temperature of 110° C.,for instance, or in other words slightly below the polyethylene meltingtemperature. The waste material can be used in its original form, forinstance with its original coloring made up of printed material or abackground color, and so forth.

The use of pieces of sheet whose volume has been increased also has theadvantage that in a simple way, under pressure, they fill out theinterstices between rows of yarn and the spaces around the yarn loopquite well.

The method for producing the tufted carpet according to the invention ischaracterized in that pieces of plastic material in sheet form is firstapplied to a uniform layer thickness, including the option of multipleplies, on the back side of a loosely tufted tufting backing and bondedto one another by the influence of pressure and temperature, preferablyby means of a warm rolling or pressing operation, so that the back endsof the tufting yarns are firmly bound in. The warm rolling or pressingoperation not only achieves better bonding of the tufting yarns to thetufting backing; it is also possible to produce carpets of differentstiffness and thickness by means of variously pronounced densificationor a variously thick layer of the pieces of sheet-like material. It isadvantageous if the sheets are heated up to their melting temperature,and the back ends of the tufting yarns are firmly bonded to the backingby means of the melting sheets and bound into the sheets. The action ofheat is exerted from the back side of the carpet, thus preventingexcessive deformation of the carpet pile.

The quantity of pieces of sheet material applied can either correspondto the quantity necessary for adequate adhesive bonding, or it may bedimensioned such that there is an excess, producing a substantiallyheavier and stiffer product. The excess pieces of sheet material canalso be mixed with another material, in order to vary the elasticity,thickness, rollability; and ease of carpet laying. For better ease oflaying, the back can be embossed or roughened.

In accordance with an advantageous feature, it may also be provided thatbefore or during the rolling or pressing operation, a second tuftingbacking is placed on the tufting backing that is provided with the layerof sheet material and is bound to the latter layer by the ensuing actionof pressure and temperature. The second backing may comprise nonwoven orwoven fabric.

If normally the tufting yarns are not bound relative to the backing,then the bonding is reinforced, especially for especially high-trafficcarpets, by providing that before the tufting yarns are tufted, i.e.,inserted, the tufting backing is provided with a layer of thermoplasticsheeting or with an adhesive layer. The layer of thermoplastic sheet maybe polyethylene, for instance, and can be placed loosely on the tuftingbacking or bonded beforehand to it. Particularly by needle punching of alayer of binding fiber, better binding of the tufting yarns to thetufting backing is attainable. The bonding of this kind of binder layerto the backing is done in particular in a single heat-pressing process,in which the layer of plastic sheeting is also applied to the backingthe tufting yarns being bound in the process.

The subject of the invention will be described in further in conjunctionwith drawings.

Shown are:

FIG. 1: a schematic, enlarged view of a tufting backing with looselyinserted yarns and with a layer of pieces of plastic sheeting.

FIG. 2: a schematic, enlarged view of the tufted carpet according to theinvention.

FIG. 3: a view corresponding to FIG. 1, with a second backing.

FIG. 4: a schematic, enlarged view of a tufting backing with looselyinserted yarns and with needle-punched binding fibers.

The tufted carpet according to the invention has a tufting backing 1with tufting yarns 2 initially inserted loosely. The tufting backing 1comprises a woven or nonwoven fabric. The tufting yarns 2, afterinsertion through the backing 1, form loops 3, and on the back side 1aof the backing 1 they extend parallel to it, forming the back ends 2a.In FIG. 1, a layer 4 of loose pieces of plastic sheeting is shown,deposited on the back side 1a of the tufting backing 1. This layer 4,under the influence of pressure and temperature, with the temperaturebeing in the range of the melting temperature of the plastic used buttypically not reaching that temperature, forms a thinner layer 5, inwhich the pieces of plastic sheeting are firmly joined together and tosome extent are in firmly adhesively bonded or molten form. The backends 2a of the tufting yarns 2 are firmly bound into this layer 5. As aresult, the tufting yarns 2 can no longer pull out of the finishedcarpet (FIG. 2). In FIG. 3, a tufting backing 1 is shown with the layer4 of piece-goods plastic sheeting and with a second back 6 before theheat-pressing process. By the influence of pressure and temperature,especially in a warm rolling or pressing operation, all the componentsare joined together to make a carpet product.

In FIG. 4, a tufting backing 1 is shown, with loosely inserted tuftingyarns 2 and with needle-punched binding fibers 7. The binding fibers 7are needle-punched into the tufting backing 1 before the yarns 2 areinserted. In their segments 7a on the back side 1a of the tuftingbacking 1, they form additional binding volumes for the back ends 2a ofthe tufting yarns 2.

We claim:
 1. A tufted carpet comprising a tufted primary backing havingpile tufts extending from one side thereof with back ends of tufts on,an opposite surface and thermally bonded to said opposite surface alayer composed of pieces of thermoplastic sheet material wherein thepieces of thermoplastic sheet material have been fused to the tuftedbacking under heat and pressure sufficient to embed said back ends inthe layer and to the primary backing, and further comprising bindingfibers of a material whose melting temperature is lower than that of thetufting yarns, which fibers are needle-punched into said oppositesurface of the tufted primary backing.
 2. The carpet of claim 1 whereinthe pieces of plastic sheet material comprise pieces of polyethylenesheets.
 3. The carpet of claim 2 wherein the plastic sheet pieces arenot flat pieces.
 4. The carpet of claim 3 wherein the plastic sheetpieces have a bulk volume that is at least one and a half times to tentimes as great as the volume of the plastic sheet material.
 5. Thecarpet of claim 1 wherein the pieces of plastic sheet material arederived from sheet trimmings.
 6. The carpet of claim 1 which furthercomprises a secondary backing.
 7. A tufted carpet comprising a tuftedprimary backing having pile tufts extending from one side thereof withback ends of tufts on an opposite surface and thermally bonded to saidopposite surface a layer composed of pieces of thermoplastic sheetmaterial wherein the pieces of thermoplastic sheet material have beenfused to the tufted backing under heat and pressure sufficient to embedsaid back ends in the layer and to the primary backing, and wherein thepieces of thermoplastic sheet material are three dimensional and have abulk volume that is one and a half to ten times as great as the volumeof the sheet material.
 8. The carpet of claim 7 wherein the pieces ofplastic sheet material comprise pieces of polyethylene sheets.
 9. Thecarpet of claim 7 which further comprises a secondary backing.
 10. Amethod for producing a tufted carpet comprising:applying a uniform layerof pieces of thermoplastic sheet material on the backside of a primarytufting backing; tufting the primary backing with tufting yarns suchthat pile tufts extend from the front side of the backing and back endsof the tufting yarns remain in the primary backing; and heating andapplying pressure to the pieces of thermoplastic sheet material to fusethe pieces to one another and to the back ends of the tufting yarns. 11.The method of claim 10 wherein heat and pressure is applied by a warmrolling or pressing operation.
 12. The method of claim 10 wherein theprimary tufting backing is needle punched with binding fibers from theback side of the tufting backing prior to the tufting step.
 13. Themethod of claim 12 wherein the binding fibers are polyethylene bindingfibers.
 14. The method of claim 10 wherein an adhesive layer is appliedto the primary tufting backing prior to the tufting step.
 15. The methodof claim 10 wherein a secondary backing is applied to the layer ofpieces of thermoplastic material prior to heating and applying pressure.